1. Field of the Invention
The present invention relates to eye protection devices. More specifically, the present invention relates to techniques for preventing eye damage due to high intensity laser radiation.
While the present invention is described herein with reference to illustrative embodiments for particular applications, it should be understood that the invention is not limited thereto. Those having ordinary skill in the art and access to the teachings provided herein will recognize additional modifications, applications, and embodiments within the scope thereof and additional fields in which the present invention would be of significant utility.
2. Description of the Related Art
The threat of the use of laser radiation to induce vision impairment has prompted a concern for the ocular welfare of personnel operating in hostile environments. This has lead to the recognition of certain requirements to insure adequate eye protection against such threats. Generally, the eye protection gear should have a broad spectrum to block incident radiation over a wide bandwidth. The eye protection device should have a zero response time to insure that the device will react quickly enough to protect the eye from short pulses of intense radiation. It should operate independent the angle and polarization of the incident radiation. It should be sensitive to energy in the visible to near infrared range. The device should have a fast recovery time and a high damage threshold.
Conventional eye protection technologies do not adequately meet these requirements. Multi-channel image intensifiers can be used as efficient image converters for eye protection. These devices utilize photosensitive materials which generate electrons. The electrons are amplified and bombarded on a phosphorous screen to create an image of a scene.
Unfortunately, the photo-cathode of image converters are typically susceptible to breakdown in response to an intense laser pulse. The recovery time from such breakdown is too slow for many current applications. And these devices tend to be complicated often requiring high voltages. This class of devices also includes electrochromic effect based goggles which tend to be too slow and have a extinction coefficient which is too low (viz., energy leakage too high) for the noted application.
Visors based on narrow band filters implemented with multiple optical thin film layers can only reject radiation at known wavelengths. No protection is provided against arbitrary radiation in the broad visible spectrum such as that resulting from a dye laser.
Nonlinear optical materials in the desired region remain as an unproven concept. No optical material is known which features sufficiently high sensitivity and response time to meet the demanding requirements of eye protection. In addition, the leakage of any such devices would probably be too high.
Thus, there is a need in the art for a broad spectrum, zero response time angle and polarization independent, sensitive eye protection device having a fast recovery time, high extinction coefficient and a high damage threshold.